<!DOCTYPE html>
<html>

<head>
    <meta charset="utf-8">
    <title>组选择器</title>
    <style>
        h1,
        h2,
        p {
            color: green;
        }
    </style>
</head>

<body>
    <h1>Hello World!</h1>
    <h2>Smaller heading!</h2>
    <p>This is a paragraph.</p>
</body>

</html>